Braz Dent J 13(2) 2002Dentofaci almorphol ogy of mouth breathi ng chi l dren 129 Braz Dent J (2002) 13(2): 129-132Dentofacial Morphology of Mouth Breathing ChildrenPatrcia Toledo Monteiro FARIA1Antonio Carlos de Oliveira RUELLAS1,2Mrian Aiko Nakane MATSUMOTO3Wilma T. ANSELMO-LIMA4Fabiana C. PEREIRA41Specialization Course in Orthodontics and Facial Orthopedics, EFOA, Alfenas, MG, Brazil2Department of Orthodontics, Faculty of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil3Discipline of Orthodontics, Faculty of Dentistry of Ribeiro Preto, University of So Paulo, Ribeiro Preto, SP, Brazil4Department of Otorhinolaryngologics, Faculty of Medicine of Ribeiro Preto, University of So Paulo,Ribeiro Preto, SP, BrazilThe relationship between dentofacial morphology and respiration has been debated and investigated from various approaches. The aimof this study was to verify the skeletal and dental relationship of mouth and nose breathing children. Thirty-five children, 7 to 10 yearsof age, were submitted to orthodontic and otorhinolaryngologic evaluations and were separated into 2 groups: 15 nose breathers and20 mouth breathers. Each subject underwent a cephalometric radiograph analysis. Statistical analysis (Mann-Whitney U test) indi catedthat changed mode of breathing was associated with 1) maxillo-mandibular retrusion in relation to the cranial base in the mouthbreathers; 2) the SNGoGn and NSGn angles were greater in the mouth breathing group; 3) incisor inclination in both jaws and theinterincisal angle were not different between groups. There was no statistically significant difference in the maxillary and mandibularmolar heights between the nose breathers and mouth breathers.Key Words: mouth breathing, malocclusion, cephalometrics.Correspondence: Profa. Dra. Mrian Aiko Nakane Matsumoto, Disciplina de Ortodontia, Faculdade de Odontologia de Ribeiro Preto, USP, Av. doCaf, s/n, 14040-904 Ribeiro Preto, SP, Brasil. E-mail: manakane@forp.usp.brISSN 0103-6440INTRODUCTIONNose breathing associated with the normal func-tions of chewing and swallowing and posture of tongueand lips provides correct muscular action stimulatingadequatefacialgrowthandbonedevelopment(1).Dentofacialmorphologycanbealteredbydysfunc-tions, such as nasorespiratory obstruction depending onthe magnitude, duration and time of occurrence (2).Whennosebreathingisdisruptedbyadenoidandtonsilhypertrophy,rhinitis,nasalseptumdevia-tion, among others (3,4), there is a prevalence of mouthbreathing. Mouth breathing may lead to postural changessuch as lowered position of the mandible, raised posi-tionofthehead,lowpostureofthehyoidboneandanterior inferior position of the tongue (1,2,5). It hasalsobeenshownthatsuchposturalchangesmayberelated to specific dentofacial characteristcs and mor-phological changes (6).According to Paul and Nanda (7), there is muchevidence that mouth breathing produces deformities ofthe jaws, inadequate positionor shape of the alveolarprocess and malocclusion and results in the develop-mentof adenoidalfacies or longfacesyndrome(8,9). The aim of the present investigation was to verifyskeletalanddentalrelationshipsofmouthandnosebreathing children.MATERIAL AND METHODSThirty-five children of both sexes ranging in agefrom 7 to 10 years were selected from the OrthodonticService of the Faculty of Dentistry of Ribeiro Preto,USP. The children were submitted to otorhinolaryngo-l ogi cal anddental eval uati onsthatconsi stedofanamnese, specific physical examination, nasofibros-copy, cavum radiographs and cephalometrical analysis.The children were evaluated in the Otorhinolaryngol-ogy Department of the Faculty of Medicine of RibeiroPreto,USPandtheywerefurtherseparatedinto2Braz Dent J 13(2) 2002130 P. T. M. Faria et al.groups: nose breathers (N = 15) and mouth breathers (N= 20) according to the results of clinical, physical andnasofibroscopic examinations and cavum radiographsbased on methods proposed by Cohen and Konak (10).Nosebreathersmetthefollowingcriteria:1)lightornoalterationintheradiographicexam;2)nasopharynxobstructionlessthan30%detectedbynasofibroscopy exam; 3) no history of orthodontic treat-ment. Mouth breathers demonstrated: 1) evident alter-ationintheradiographicexam;2)nasopharynxob-structiongreaterthan60%(somepatientspresented100% obstruction that could be associated to allergicrhinitis, hypertrophy of palatal tonsil, among others); 3)no history of orthodontic treatment.Standard lateral cephalometric radiographs wereobtained to evaluate the skeletal and dental characteris-ticsofbothgroups.Thecephalometricradiographswere traced on 0.002 inch acetate paper and dental andskeletal anatomic landmarks were located and used forthe angular and linear measurements (Figure 1).The data were submitted to statistical analysisusing the GMC program, 7.7 version. The non-para-metricMann-WhitneyUtestwasused.Thelevelofsignificance was set at p